In general, exhaust pipes function to expel waste gases produced in the combustion chamber of an engine. For this reason, the exhaust pipe is fluidically connected on one end thereof to an exhaust port of the engine and have an exit port located spaced apart from the engine, generally near the rear of a vehicle. The exhaust pipe thus extends along the length axis of the vehicle. Generally, in the past, the exhaust pipe has been located near the longitudinal centerline of vehicle.
Today's new vehicles normally are not provided with exterior steps. Therefore, many pickup truck owners add steps to their trucks just below either the driver's side door or the passenger's side door, or below both these doors. The reasons for adding steps to a truck include both functional and aesthetic considerations.
Steps make entering the truck's cab easier, particularly for very young or old people, for individuals having short legs, and for person's wearing garments, such as tight skirts, which restrict the height which the individual's leg and foot may be raised in order to step into the cab.
Therefore, the steps must be strong in order to support the weight of a person as he or she enters and exits the cab. Strictly from a standpoint of strength, the ideal material for constructing a truck step would be mild or carbon steel. However, steps constructed of mild steel are generally not very attractive, even if painted, and the carbon steel will eventually rust from the moisture it is exposed to in this service. Thus truck steps constructed of carbon steel are not very popular with truck owners.
On the other hand, from a purely aesthetic standpoint, truck steps constructed of stainless steel are most attractive. Additionally, stainless steel truck steps remain attractive for years because stainless steel does not rust like mild steel when exposed to the elements. However, stainless steel is a more expensive material than mild steel. Also stainless steel is difficult and costly to shape into the proper configuration to form a truck step and to polish after being properly formed. In order to reduce the cost of their product and thereby make their product more cost competitive in the marketplace, some manufacturers of truck steps have reduced the thickness of the stainless steel used in constructing their steps and have reduced support structures employed to secure the steps to the truck frame. As a result of such changes, these stainless steel truck steps, although quite attractive, are essentially non-functional because they are so structurally weak that they cannot bear the weight of an individual without bending or breaking completely off the vehicle.
Many vehicles, particularly, heavy duty trucks, specifically those of a cab-over-engine configuration, are known for poor cab accessibility due to the presence of a large front wheel below the cab entrance. In this respect, previous cabover heavy duty trucks offer only narrow steps within the body for a driver as he climbs up into the cab. Further, the area of a truck body within which a step may be formed is restricted in height by the cab structure itself, i.e., the space available between the cab floor and the underlying wheel well, or the height of a bumper side wall.
On the other hand, the aerodynamics of a truck cab can be substantially compromised by attachments, such as steps, extending beyond the body of the cab during operation, especially at highway speeds, resulting in additional parasitic power usage with a corresponding reduction in fuel economy and increased emissions.
Various types of steps can be added onto a pickup truck to allow a person to step thereon in order to facilitate the person's entry and exit from the pickup. One such step is a universal stainless steel truck step disclosed in U.S. Pat. No. 5,501,475 granted on Mar. 26, 1996.
The drawback with each of these add-on types of vehicle steps is that they rigidly attach to the vehicle and extend outward from under the vehicle where they can be in the way when they are not being used.
There is further need for a workable step into a motor vehicle as evidenced by the fact that, in many large vehicles such as a Class A motorhome the floor in the driver's area is often 3½ feet or more above the ground. Also in many of these large vehicles the driver sits nearly over the front wheel. It is impractical to employ a retractable step of the type commonly used in the middle of the passenger side on many Class A motorhomes, since it would have to be installed where the front wheel is located.
Therefore, there is a need for a step device for use on a land vehicle which is efficient and does not detract from the overall efficiency of the vehicle.